PASS LABS INT-150 or X-250 with X-1

I would also consider the INT-30A which is based on the XA.5 series. The power spec is conservative though it may not have enough for your speakers with which I am unfamiliar. You should contact Pass with this question. Kent is very good at describing differences in the product line. If you have a local Pass dealer, audition the different suggestions in your system if possible.

Zeebee:
thanks,i'm just looking to add some warm sound in my set up.
but i will consider to change to series X.5 if that is the route.
Gundam:
maybe i will love the X350.5 but now i can only get the X250.5
as my budget allow.)
Peterayer:
awesome system u have there.)
power rate really my concern,the amp now push class A around first 40w,but i still thinking not enough.

My comments were meant to touch on the subject of how different the X .5 series is from the non .5 series. The comments I made for the X350.5 vs. X350 should also apply to X250.5 vs. X250.

There are just as many people that will say that X250.5 is better than X350.5 as the other way around. Since I own the X350.5, I cannot be objective. ;-) I don't know anyone local with an X250.5. Otherwise, I would love to do a side-by-side shootout.
FrankC

I have heard both the X350 and the X350.5 and I do not think they sound as differently as everyone has been saying. I have auditioned both courtesy of members of my audio club. I do hear more detail in the X350.5 but the signature is still the same. I think that what I heard is borne out in the changes that Nelson has made in the X.5 series. He replaced the front end Fets with Jfets that have much lower noise. I think thats where the extra detail comes from. The extra output devices will give a little more power but I think it does not change the amplifier's signature. Pass always biased his amplifiers pretty hard to get the output fets to operate a little more linear. Does the X350.5 sound better? Absolutely! The details are more apparent in the X.5 amps but the amps have the same sonic signature and do sound very similar with the X.5 amps revealing some hidden details.

I own a Bel Canto DAC3, and have owned an X1 pre which I have upgraded to a Pass XP10. I'd characterize the X1 on the cooler side of neutral. If you are looking for more warmth and dynamics, I'd urge you to go to an XP10. It will also add a bit of bass warmth too, but still keep the depths you have been getting. I have run the DAC3 direct as a pre, and didn't get the dynamics and soundstage I wanted, but am getting it in droves with the XP10. There have been a few offered here around 3K lately, which is a bargain for the quality. Good luck!